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Journal Cover Reactive and Functional Polymers
  [SJR: 0.879]   [H-I: 62]   [5 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1381-5148
   Published by Elsevier Homepage  [2970 journals]
  • Self-Organization and Phase Transformation of All π-Conjugated
           Diblock Copolymers and Its Applications in Organic Solar Cells
    • Abstract: Publication date: Available online 18 June 2016
      Source:Reactive and Functional Polymers
      Author(s): Ching Shen, Yi-Huan Lee, Yu-Ping Lee, Chi-Ju Chiang, Fan-Kai Wei, Chia-Hung Wu, Kuo-Chang Kau, Hung-Wei Liu, Chih-Chen Hsieh, Leeyih Wang, Chi-An Dai
      In this study, we report on the synthesis and the self-assembling behavior of a series of monodisperse all π-conjugated poly(2,5-dihexyloxyp-phenylene)-block-(3-hexylthiophene) (PPP-P3HT) block copolymer system and construct their phase diagram that exhibits diverse nanostructures of predominant PPP nanofibers, PPP-P3HT lamellae, broken lamellae and predominant P3HT nanofibers as a function of the copolymer composition. An order-to-disorder phase transition is also observed for the copolymers at a temperature above the melting point of the predominant blocks, indicating the rod-rod interaction between the π-conjugated chains plays a key role in the formation and the stabilization of the observed nanostructures. In particular, we have also found that the incorporation of PPP segments to P3HT to form nanofibrillar structure significantly enhance the self-organization behavior of the P3HT in the copolymer. The improvements in crystallinity and mobility for the copolymers therefore substantially enhance their solar cell performance. The use of this novel material with diverse nanostructures provides a new strategy to enhance photovoltaic performance and shows the potential for use in future optoelectronic applications.


      PubDate: 2016-06-18T18:05:28Z
       
  • Poly(ionic liquid) Prepared by Photopolymerization of Ionic Liquid
           
    • Abstract: Publication date: Available online 18 June 2016
      Source:Reactive and Functional Polymers
      Author(s): Shen-Mei Chen, Tzong-Liu Wang, Pei-Yu Chang, Chien-Hsin Yang, Yi-Chao Lee
      Vinylimidazolium-typed poly(ionic liquids) (PILs) are prepared by photo- polymerization of ionic liquid monomers. Vinylimidazolium-based ionic liquid monomers with C4 and C8 alkyl tail length were synthesized via quaternization of 1-vinylimidazole with corresponding n-alkyl bromides. Polymerization was conducted at a 3wt% of photoinitiators in these monomers using illumination of 36W LED light. In the same procedure, preparation of cross-linked PILs was performed in the presence of 15 mole % of divinylimidazolium-based cross-linker. These PILs are characterized by using chemical structure, physical characteristics, and electrical conductivity. Electrical conductivity of C4-based PILs is greater than that of C8 -based PILs, whereas linear PILs are higher than crosslinked PILs. Crosslinked PILs have higher glass transition and thermal decomposition temperatures as compared linear PILs. PILs consist of the repeating units of anion and cation pair. Its nature has moderate electronic conductivity, which is suitable use in gel-type or quasi-solid-state dye-sensitized solar cells (DSSCs). The linear PILs were incorporated in DSSCs obtaining an efficient quasi-solid-state cell to solve the leakage of liquid electrolyte in a liquid-type DSSC.


      PubDate: 2016-06-18T18:05:28Z
       
  • Structure of hydrogen bonded supramolecular self-assembles controlled by
           the structure of monomers: 1,1- and 1,3-diethylureas
    • Abstract: Publication date: Available online 7 June 2016
      Source:Reactive and Functional Polymers
      Author(s): Jolanta Świergiel, Jan Jadżyn
      Asymmetrically disubstituted 1,1-diethylurea, the moiety HNH·CO of which is capable of forming intermolecular hydrogen bonds with the possibility of creating two extremely different supramolecular entities: i) highly polar polymeric chains, analogous to those created by secondary amides, and ii) non-polar cyclic dimers, analogous to those created by lactams, in the experiment reveals exclusively the cyclic dimers. A solution of 1,1-diethylurea in non-polar solvent (with the mole fraction of urea 0.04) exhibits very low permittivity (about 3) what is in marked contrast to the permittivity (about 11) of analogous solution of symmetrically disubstituted 1,3-diethylurea, known for its strong chain polymerization.The difference of two orders of magnitude in the electrical conductivities of 1,1- and 1,3-diethylurea (ionically undoped) solutions suggests a probable participation in the conductivity of the protons released in process of thermal rupture of the hydrogen bonds linking 1,3-diethylurea molecules in supramolecular polymeric chains.


      PubDate: 2016-06-15T13:31:59Z
       
  • MALDI-TOF analysis of lactide oligomers with functional end groups
    • Abstract: Publication date: July 2016
      Source:Reactive and Functional Polymers, Volume 104
      Author(s): Marcin Florczak, Adam Michalski, Anna Kacprzak, Marek Brzeziński, Tadeusz Biedroń, Agnieszka Pająk, Przemysław Kubisa, Tadeusz Biela
      Medium molecular weight polylactides (PLAs) with different end groups were synthesized and analyzed by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. Four types of end groups were introduced as head group using appropriate initiators: cationic group [ionic liquid group (IL-PLA-OH)], easily ionizable groups [aminopyridine group (AmPy-PLA-OH) and terpyridine group (TerPy-PLA-OH)], and neutral group [butoxy group (Bu-PLA-OH)]. MALDI-TOF spectra were recorded with various cationizing agents (Li+, Na+, and K+ salts). Different modes of ionization were observed depending on the nature of end group. These various modes of ionization lead to different ionization efficiencies, which affect signal intensity. Moreover, analysis of 1/1 mixtures showed that in spectra of mixtures of IL-PLA-OH with either AmPy-PLA-OH or Bu-PLA-OH, only the signals of IL-PLA-OH were detected, while in the spectrum of AmPy-PLA-OH with Bu-PLA-OH, the former gave signals with intensity about one order of magnitude higher than the latter. Such discrimination resulting from different modes and efficiencies of ionization of macromolecules containing structurally different end groups may lead to erroneous conclusions.


      PubDate: 2016-06-15T13:31:59Z
       
  • Linear amphiphilic TEMPO-grafted poly(ether sulfone) as polymeric
           interfacial catalyst: Synthesis, self-assembly behavior, and application
    • Abstract: Publication date: Available online 15 June 2016
      Source:Reactive and Functional Polymers
      Author(s): Liang Chen, Jun Tang, Qi Zhang, Jianli Wang
      In this study, we report the development of a novel recyclable polymer-supported interfacial catalyst for Montanari oxidation. The catalyst was prepared by immobilization of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) on poly(ether sulfone) (PES) bridged by imidazole groups and characterized by 1H nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, elemental analysis, contact angle measurement, and transmission electron microscopy (TEM). This well-designed polymer was self-assembled into nanoaggregates in CH2Cl2. It was then used as Pickering emulsifier in Montanari oxidation system (NaClO/NaBr/immobilized TEMPO) for selective oxidation of different alcohols, which exhibited higher activity due to the enhanced mass transfer through microreactor mechanism. Moreover, this polymeric interfacial catalyst was pH-sensitive and could be easily recycled by adding small amount of acid, and subsequent cycles of alcohol oxidation showed no loss on either conversion or selectivity. This study represents an innovative approach for developing polymeric interfacial catalyst.
      Graphical abstract image

      PubDate: 2016-06-15T13:31:59Z
       
  • Editorial Board
    • Abstract: Publication date: July 2016
      Source:Reactive and Functional Polymers, Volume 104




      PubDate: 2016-06-15T13:31:59Z
       
  • Editorial Board
    • Abstract: Publication date: June 2016
      Source:Reactive and Functional Polymers, Volume 103




      PubDate: 2016-06-15T13:31:59Z
       
  • Pyrene or rhodamine derivative–modified surfaces of electrospun
           nanofibrous chemosensors for colorimetric and fluorescent determination of
           Cu2+, Hg2+, and pH
    • Abstract: Publication date: Available online 1 June 2016
      Source:Reactive and Functional Polymers
      Author(s): Chia-Jung Cho, Shih-Tung Lu, Chi-Ching Kuo, Fang-Cheng Liang, Bo-Yu Chen, Chien-Chia Chu
      Novel fluorescent nanofibrous nonwoven-state sensors exhibiting high sensitivity to heavy metal ions were prepared from pyrene derivative (PyDAN2) or rhodamine B derivative (RhBN2)–modified poly(2-hydroxyethyl methacrylate-co-N-methylolacrylamide) (poly(HEMA-co-NMA)) electrospun (ES) nanofibers by employing a single-capillary spinneret. The HEMA moieties were designed to exhibit hydrophilic properties, and the NMA content substantially affected the stability of the ES nanofibers in water as well as enhanced their endurance in various organic solvents. PyDAN2 and RhBN2 grafted onto the cross-linked poly(HEMA-co-NMA) ES nanofibers through surface-initiated polymerization were denoted as Fiber-g-PyDAN2 and Fiber-g-RhBN2, respectively; they exhibited highly selective detection capabilities for copper (Cu2+) and mercury (Hg2+) ions/pH, respectively. The fluorescence emission colors of Fiber-g-PyDAN2 and Fiber-g-RhBN2 were initially nonfluorescent, but they transformed into strong fluorescence emissions with blue and orange-red colors when they detected Cu2+ and Hg2+/pH, respectively. These sensors have high reversibility because their on–off switchable fluorescence emissions cycled several times upon the sequential addition of Cu2+/Hg2+ and EDTA or acidic and alkaline media. The prepared chemosensors can be grafted onto ES nanofibrous membranes and can be used as “naked eye” sensors. They have potential applications in environmental sensing devices, especially in pollution sensors.


      PubDate: 2016-06-15T13:31:59Z
       
  • Deposition of Au nanoshells on thermally grown patterned Ag nanoparticles
           from the block copolymer micelle thin films by seeding method
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Himadri Acharya
      A facile method of fabricating patterned Ag–Au core–shell nanoparticles has been demonstrated using stepwise reduction and seeded deposition from block copolymer (BCP) micelle thin films. Spherical inverse micelles of polystyrene-block-poly(4-vinyl pyridine) (PS-b-P4VP) copolymer in PS-selective toluene produce organic–inorganic complexes by coordinating silver acetate salt (Ag salt) to the hydrophilic P4VP core. Rapid thermal decomposition of Ag salt-loaded BCP micelles at 300°C for 5min leads to the formation of stable Ag nanoparticles of 20–25-nm size on a quartz substrate. The variations in annealing temperature, time, and substrate types influence the resulting Ag nanostructures. Transmission electron microscopy investigations reveal that gold (Au) shells of approximately 2.5-nm size on the Ag nanoparticles have been deposited by the seeding method using a selective reducing agent. Ag–Au core–shell nanoparticles can also help to control the hybridized surface plasmon band.


      PubDate: 2016-06-15T13:31:59Z
       
  • Adsorption and release studies of cefuroxime sodium from acrylic ion
           exchange resin microparticles coated with gellan
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): S. Racovita, M.A. Lungan, I. Bunia, M. Popa, S. Vasiliu
      Two types of microparticles based on acrylic ion exchange resin were prepared and used as macromolecular supports for the adsorption of an antibiotic (cefuroxime sodium salt) from aqueous solution. The first type of microparticles was synthesized by aqueous suspension copolymerization of acrylonitrile, ethylacrylate and ethylene glycol dimethacrylate followed by the aminolysis reaction of ternary copolymer with hydrazine hydrate. For the preparation of the second type of microparticles the gellan was selected to cover the surface of acrylic ion exchanger in order to increase the biocompatibility of these systems. Batch adsorption studies regarding the effects of various parameters such as, temperature, contact time, initial concentration of drug, drug:microparticles ratio and pH were studied. To study the adsorption kinetic mechanism, the Lagergren, Ho, Elovich and Weber-Morris particle diffusion models were applied and it was found that the adsorption of the drug could be described by pseudo first order equation (Lagergren model). The calculated values of thermodynamic parameters (ΔG, ΔH, ΔS) showed that the adsorption process was spontaneous and endothermic. The drug release process was found to be controlled by diffusion of drug molecules through polymer networks.


      PubDate: 2016-06-15T13:31:59Z
       
  • Energy-level tuning of poly(p-phenylenebutadiynylene) derivatives by click
           chemistry-type postfunctionalization of side-chain alkynes
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Dong Wang, Ruirui Zhang, Hong Gao, Xiangke Wang, Huihui Wang, Zhou Yang, Wanli He, Hui Cao, Jianming Gu, Huiying Hu, Huai Yang
      A series of poly(p-phenylenebutadiynylene) polymers substituted with electron-rich alkynes as the side chain were synthesized by homocoupling polymerization of asymmetric bifunctional monomers. The electron-rich alkynes underwent “click chemistry” with tetracyanoethylene (TCNE) to produce donor–acceptor chromophores. Optical and electrochemical characterizations clearly indicated that the energy level and band gap of P2 could be precisely controlled by the addition of acceptor molecules. One of the most important conclusions of this study is that a linear relationship between the lowest occupied molecular orbital (LOMO) and the amount of TCNE was observed. From the Z-scan measurement, all the compounds exhibited very special nonlinear optical properties, which suggested a tendency to transfer from saturable absorption (SA) to reverse saturable absorption (RSA).


      PubDate: 2016-06-15T13:31:59Z
       
  • Ultrafast and efficient removal of cationic dyes using a magnetic
           nanocomposite based on functionalized cross-linked poly(methylacrylate)
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Ali Pourjavadi, Azardokht Abedin-Moghanaki
      In this study, a new magnetic nanocomposite was synthesized via radical polymerization of methyl acrylate onto modified magnetic nanoparticles followed by the functionalization of the methyl ester groups with ethylenediamine and sodium chloroacetate. The generated magnetic nanocomposite was characterized by FT-IR, TEM, SEM, TGA, VSM, XRD and elemental analysis. Its key role as an adsorbent for the removal of typical cationic dyes, methyl violet and malachite green was investigated in terms of pH, contact time and initial dye concentration. The resulted adsorbent displays excellent adsorption capacities for cationic dyes which are more effective than most of the adsorbents reported so far. Study of the kinetic and isotherm of adsorption indicated that dyes adsorption process is well-described by pseudo-second-order-kinetic and Langmuir isotherm models, respectively. Furthermore, to find an accurate correlation between the adsorption enthalpy (ΔH) and experimental maximum adsorption capacity (qm), calculation of the adsorption enthalpy of a series of cationic dyes onto MNC-EDDA adsorbent was investigated using density functional theory (DFT). Interestingly, an excellent agreement between experimental qm and calculated ΔH (kcal/mol) was found which is able to predict the maximum adsorption capacities onto the prepared adsorbent for the other cationic dyes.


      PubDate: 2016-06-15T13:31:59Z
       
  • Evaluation of the use of solvent impregnated resins in the analysis of
           salbutamol in human urine followed by capillary electrophoresis
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Irma Pérez-Silva, Ma. Teresa Ramírez-Silva, Carlos A. Galán-Vidal, Giaan A. Álvarez-Romero, José A. Rodríguez, Ma. Elena Páez-Hernández
      In this work, a method for sorption and concentration of salbutamol in urine combined to capillary electrophoresis with UV detection was performed. The procedure is based on the sorption of salbutamol on solvent-impregnated resins that is prepared by an impregnation technique using Aliquat 336 as extractant and XAD-4 resin as the base polymer. Batch studies showed an efficient sorption/desorption results when the salbutamol solution contains NaOH 0.05molL−1 and the eluent is 0.5molL−1 NaCl. Linearity was obtained in the range of 1000–10,000ngmL−1 of salbutamol. The limit of quantification was 999ngmL−1. The solvent-impregnated resin was used for 10cycles without a significant loss of the salbutamol quantification capacity. The method was applied to analyze salbutamol in urine samples at levels useful for international health organizations. Although most reports of solvent impregnated resins are related to the extraction of metal ions and only a few organic compounds, the proposed methodology demonstrate that solvent impregnated resins allows the isolation and concentration of salbutamol from complex samples such as urine. Since no SB is recovered using resin without Aliquat 336, this work shows an advantage of SIR over simple adsorption processes.


      PubDate: 2016-06-15T13:31:59Z
       
  • Preparation of polyaniline-coated polystyrene nanoparticles for the
           sorption of silver ions
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Saurabha Bhattarai, Jong Soo Kim, Yeoung-Sang Yun, Youn-Sik Lee
      Polyaniline-coated polystyrene (PS/PANI) beads with an average diameter of approximately 310nm were prepared from styrene and divinylbenzene via emulsion polymerization and subsequent oxidative polymerization of aniline. The sorption capacity of the polymer beads towards silver ions in aqueous solution increased substantially as the pH increased, up to a pH of 7, owing to more free amine and imine groups. The FE-SEM images and XRD data indicated that silver ions were reduced to form silver nanoparticles on the polymer beads. The kinetics of silver ion uptake by PS/PANI particles in a 160ppm silver nitrate solution could be described by a pseudo-second order model. Even though the sorption isotherm correlated to the Freundlich model much better than the Langmuir model, the Langmuir model-based maximum sorption (320mgg−1) was closer to the experimentally obtained value of 330mgg−1. This study reveals that PS/PANI beads can be readily prepared in large quantities and employed as one of most efficient sorbents of silver ions in the aqueous phase. The high sorption capacity of the polymer nanoparticles was illustrated not to be affected by common alkali and alkaline earth metal ions in a simulated tap water. The PS/PANI nanoparticles were stable enough not to show any significant loss in sorption efficiency even after fourth cycle of adsorption-desorption.
      Graphical abstract image

      PubDate: 2016-06-15T13:31:59Z
       
  • A review of the fabrication of photonic band gap materials based on
           cholesteric liquid crystals
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Rathinam Balamurugan, Jui-Hsiang Liu
      Cholesteric liquid crystals (CLCs) are known to exhibit selective reflection of incident radiation due to their periodic helical structure, which makes them promising candidates for a myriad of different photonic applications. At normal incidence, CLCs reflect circularly polarized incident light of the same handedness as the cholesteric helix and of wavelength λ between noP and neP, where no and ne are the ordinary and extraordinary refractive indices, respectively, of the locally uniaxial structure, and P is the pitch of the helix. Thus, the reflection bandwidth Δλ is given by Δλ=ΔnP, where the birefringence Δn=ne −no. Within the bandwidth, right-circularly polarized light is reflected by a right-handed helix, whereas left-circularly polarized light is transmitted. Outside the bandwidth, both polarization states are transmitted. Therefore, Δλ depends on Δn. Moreover, Δn is typically limited to 0.3–0.4 for colorless organic compounds, and Δλ is often <100nm in the visible spectrum. Although a narrow reflection band is desirable for applications such as optical filters and thermal imaging, it also becomes a drawback in their applications, such as reflective displays, broadband circular polarizers and switchable mirrors. The purpose of this review is to take a closer look into how to broaden the reflection band in CLCs to overcome the above limitations for a wide variety of applications. This review covers the methodology that was used until recently, when the fabrication of photonic band gap (PBG) materials arose, based on CLCs. The mechanisms for broadening the reflection band have been reviewed.


      PubDate: 2016-06-15T13:31:59Z
       
  • Architecture of Ba/alginate/dextran stabilized Au, Fe3O4, TiO2 &amp;
           silica nanoparticles gels and their applications for reduction of
           4-nitrophenol and glucose sensing
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Molly Thomas, Gowhar Ahmad Naikoo, Mehraj Ud Din Sheikh, Mustri Bano, Farid Khan
      An innovative method is presented to produce anisotropically ordered capillaries and small pores by dissipative convective process followed by simple freezing in liquid nitrogen of Ba/alginate/dextran hydrogels with and without nanoparticles. Magnetite, gold, silica or titanium dioxide nanoparticles were encapsulated safely into the gels with protecting their stability and microstructures. Mechanical strength and rheological studies of the gels were also investigated. Ba/alginate/dextran/Au composite gel has shown excellent catalytic activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in presence of NaBH4 with a rate constant of 6.85×10−3 min−1. Ba/Alg/Dex/Au-GCE exhibits non-enzymatic electrocatalytic oxidation of glucose with linear range from 1mM to 10mM (r=0.998) and the detection limit to 63μM at a signal-to-noise ratio of 3.


      PubDate: 2016-06-15T13:31:59Z
       
  • Multi-stimuli-responsive semi-IPN cryogels with native and anionic potato
           starch entrapped in poly(N,N-dimethylaminoethyl methacrylate) matrix and
           their potential in drug delivery
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Ecaterina Stela Dragan, Diana Felicia Apopei Loghin, Ana-Irina Cocarta, Mirela Doroftei
      This study was focused on the preparation of novel multi-stimuli-responsive semi-interpenetrating polymer networks (semi-IPN) hydrogels by cross-linking polymerization of N,N-dimethylaminoethyl methacrylate (DMAEM) in the presence of potato starch (PS) or anionically modified PS by using ice-templating strategy (−18°C). Cryogelation was used for this aim because it allowed decreasing the monomer concentration to 10wt.% and a very fast response at swelling of the composite gels. Furthermore, the anionically modified PS allowed the decrease of the volume phase transition temperature (VPTT) of the composite cryogels by its electrostatic interactions with the matrix. After the characterization of the composite structure by Fourier transform infrared spectroscopy and of the macroporous morphology by scanning electron microscopy analysis, the effect of the entrapped polysaccharide on the swelling properties of the composite cryogels, and their response at three stimuli (pH, temperature and ion nature and concentration) were deeply investigated. The VPTT of the composite cryogels was situated in the range 36–39°C, the particular value depending on the DMAEM concentration and on the nature and content of polysaccharide. After that, diclofenac sodium (DS), taken as a model acidic drug, was easily loaded into the composite cryogels by the solvent sorption–evaporation strategy due to the interconnected pores of these materials. The controlled delivery of DS from the novel semi-IPN composite cryogels was then optimized by the investigation of the effects of pH, temperature, and cycling changes of the release temperature. It was found that these composite cryogels are promising systems for the sustained delivery of DS in the simulated intestinal fluid, but not in the simulated gastric fluid, and this recommends them as vehicles of drugs in colon. Finally, the release mechanism of DS from the composite cryogels was discussed based on two kinetic models.


      PubDate: 2016-06-15T13:31:59Z
       
  • Conducting semi-interpenetrating polymeric composites via the preparation
           of poly(aniline), poly(thiophene), and poly(pyrrole) polymers within
           superporous poly(acrylic acid) cryogels
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Nurettin Sahiner, Sahin Demirci
      In this study, a novel and special form of hydrogel known as cryogel with super and interconnected pore structures was synthesized as p(acrylic acid) (p(AAc)) cryogel by a cryopolymerization technique. Then, the superporous p(AAc) cryogels were used as template for the synthesis of conductive polymers such as poly(aniline) (p(An)), poly(thiophene) (p(Th)), and poly(pyrrole) (p(Py)). To the best of the authors' knowledge, this is the first study of its kind to report the synthesis of conductive polymers, p(An), p(Th), and p(Py), within the superporous network of cryogel. The synthesized p(AAc)/p(An), p(AAc)/p(Th), and p(AAc)/p(Py) conducting semi-interpenetrating polymeric network (semi-IPN) cryogel composites were characterized by using Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), and conductivity measurements. The conductivities of p(AAc)/p(An), p(AAc)/p(Th), and p(AAc)/p(Py) toward semi-IPN cryogels were measured as 2.2×10−4 ±1×10−5, 3.2×10−4 ±0.9×10−5, and 3.2×10−3 ±5×10−4 Scm−1, whereas the conductivity of bare p(AAc) cryogels was calculated to be about 3.2×10−9 ±2.1×10−10 Scm−1.


      PubDate: 2016-06-15T13:31:59Z
       
  • Utility of PCDTBT polymer for the superior sensing parameters of
           electrical response based relative humidity sensor
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Qayyum Zafar, Khaulah Sulaiman
      In the present study, organic polymer PCDTBT has been deposited on pair of planar aluminium (Al) electrodes to construct an integrated capacitive and impedance type humidity sensor (Al/PCDTBT/Al). The solution processable organic polymer has been deposited through a facile spin coating technique. The structural characterization and surface morphology study of active layer has been performed by XRD and AFM. The humidity sensing characteristics of the sensor have been investigated by exposing the organic active layer to various wide range relative humidity (%RH) levels (15–98%RH) at room temperature. The proposed sensor exhibits significantly higher sensitivity ~39.73pF/%RH and 821.81kΩ/%RH when operated in capacitive and impedance mode, respectively. In addition, the capacitive sensor has desirable reproducibility, narrow hysteresis (~5%), fast response (8s) and reset (14s) time. Significantly improved sensing parameters suggest that the proposed sensor may be implemented meritoriously for continuous humidity assessment in environment.


      PubDate: 2016-06-15T13:31:59Z
       
  • Metal nanoparticles designed PET: Preparation, characterization and
           biological response
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): A. Reznickova, J. Siegel, N. Slavikova, Z. Kolska, M. Staszek, V. Svorcik
      In this manuscript, Ar plasma treated polyethyeterephthalate grafted with biphenyl-4,4′-dithiol interlayer and subsequently with green synthesized Pt and Pd nanoparticles is studied, focusing on the cytocompatibility of those composites. Changes in surface properties of the plasma treated and nanoparticle-grafted PET surface were studied in relation to in vitro adhesion and proliferation of mouse fibroblasts (L929) and human osteoblast (U-2 OS). Prepared samples were studied by several experimental techniques: goniometry, angle resolved X-ray photoelectron spectroscopy (ARXPS), ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDS) and electrokinetic analysis. Ageing of the modified PET was accompanied by an increase of the contact angle which was due to a reorientation of the molecular polar segments produced during the plasma treatment. FTIR, UV–vis, ARXPS measurements and zeta potential indicate that the thiols were chemically bonded to the surface of the plasma treated polymers and that the thiols mediate subsequent grafting of Pt and Pd nanoparticles. Generally, EDS revealed that Pt nanoparticles are homogeneously distributed over the whole surface and Pd nanoparticles tend to aggregate slightly. In case of L929 cells, the chemical anchoring of Pt nanoparticles to PET surface significantly enhanced cell adhesion and proliferation compared to pristine PET.
      Graphical abstract image

      PubDate: 2016-06-15T13:31:59Z
       
  • Dendrons with urea/malonamide linkages for gate insulators of n-channel
           organic thin film transistors
    • Abstract: Publication date: Available online 11 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Yu-Yi Hsu, Shih-Chieh Yeh, Shih-Hsun Lin, Chin-Ti Chen, Shih-Huang Tung, Ru-Jong Jeng
      A series of urea/malonamide dendritic molecules were prepared as gate insulators for organic thin film transistors (OTFTs). This series of molecules with different degrees of branching possess peripheral stearyl groups are dendrons generation 0.5 (G0.5), generation 1 (G1), generation 1.5 (G1.5), generation 2 (G2) and generation 2.5 (G2.5). In addition, two types of tetracarboxylic diimide derivatives, i.e. perylene diimide (PDI) and naphthalene diimide (NDI) with two different chain lengths of fluorinated alkyl end groups were prepared as semiconductors for OTFTs such as NDI-C4F7, NDI-C7F9, PDI-C4F7 and PDI-C7F9. The n-channel types of OTFTs were fabricated by spin-coating the gate insulators on Si/SiO2 substrates, and then depositing the semiconducting layers in vacuum without heating the substrate. Silver was used as contact electrodes for source and drain. The performance of OTFTs with dendrons as gate insulators were better than that of OTFTs modified by octadecyltrichlorosilane (ODTS). Moreover, the threshold voltages (V ths) of OTFTs shifted from positive voltage to negative voltage as the device was incorporated with higher generation of dendrons. This is because of different dielectric constants or surface energies between the interface of gate insulator and semiconducting layer. Among all samples in this study, the n-channel OTFT comprising PDI-C4F7 and G1.5 exhibited the best performance. In addition, an enhanced electron mobility and I on/I off ratio measured under ambient condition were 4.71×10−4 cm2 V−1 s−1 and 7.7×103, respectively. Apart from that, the influence of semiconducting molecular packing order on dendron gate insulator layers was investigated by grazing-incidence wide-angle X-ray scattering (GIWAXS) and atomic force microscopy (AFM). Furthermore, pentacene-based p-channel OTFTs with G1.5 gate insulator also exhibited the highest performance. These OTFTs achieved 0.1cm2 V−1 s−1 and 6.3×104 for mobility (μ) and I on/I off ratio, respectively.


      PubDate: 2016-05-16T19:02:11Z
       
  • Covalent Biofunctionalization of Chitosan Nanofibers with Trypsin for High
           Enzyme Stability
    • Abstract: Publication date: Available online 12 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Jana Srbová, Marcela Slováková, Zuzana Křípalová, Monika Žárská, Martina Špačková, Denisa Stránská, Zuzana Bílková
      The electrospun chitosan nanofibers provide excellent material for immobilized proteolytic enzymes, and are biocompatible, nontoxic and hydrophilic matrices with large specific area. This paper deals with an application of electrospun chitosan nanofibers and optimizing conditions for their biofunctionalization by model proteolytic enzyme trypsin. Nanofibers from chitosan were prepared using NanospiderTM technology and covalent immobilization of trypsin followed. Three immobilization techniques preserving biocompatibility and utilizing amine and/or hydroxyl groups of chitosan were optimized and compared to simple adsorption to achieve maximum proteolytic activity per cm2 of the functionalized chitosan nanofibers (Tryp-NF). Significant differences were observed. Trypsin immobilized by the carbodiimide one-step protocol demonstrated the highest activity of the three procedures, ranging from 132 to 210IU/cm2 (i.e., 548–874IU/mg of nanofibers), depending on the initial amount of trypsin used. Long-term storage stability together with high reusability of Tryp-NF confirmed advantages of the immobilized enzyme. Tryp-NF showed no cytotoxicity toward growth of HeLa cells. The in vivo tests for irritation and skin sensitization demonstrated no undesirable skin reactions.


      PubDate: 2016-05-16T19:02:11Z
       
  • Preparation and Application of Poly(AMPS-co-DVB) to Remove Rhodamine B
           from Aqueous Solutions
    • Abstract: Publication date: Available online 7 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Luanluan Zhang, Hejun Gao, Yunwen Liao
      A series of functional cross-linked polymer (Poly(AMPS-co-DVB)) were synthesized by 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and divinylbenzene (DVB). The physicochemical properties of the Poly(AMPS-co-DVB) were characterized by FT-IR, TGA, SEM, XRD, Zeta potential and UV–Vis. Those results showed that the Poly(AMPS-co-DVB) could provide mounts of adsorption sites from its special structure. The effects of the initial pH, dosage, contact time, and temperature on the adsorption of Rhodamine B (RhB) onto the Poly(AMPS-co-DVB) were investigated. It was found that the initial pH was an important factor for the molecules form of RhB and the surface formation of Poly(AMPS-co-DVB). With increasing of molar ratio of AMPS/DVB, the adsorption efficiency increased gradually. In the adsorption process, both physical and chemical mechanism is presence to adsorb RhB. The maximum adsorption capacity could get 407.9mg/g within 2h at room temperature.


      PubDate: 2016-05-10T18:54:30Z
       
  • New high-solubility aromatic polyesters with pendent phenothiazine:
           Synthesis, electrochromic and optoelectronic properties
    • Abstract: Publication date: Available online 9 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Xiaochuan Ma, Haijun Niu, Wanan Cai, Tiandi Xiao, Cheng Wang, Xuduo Bai, Yanhong Zhang, Wen Wang
      A series of aromatic polyesters were synthesized from dicarboxylic acids, containing pendent triphenylamine substituted with phenothiazine, and five different kinds of bisphenols. The aromatic polyesters exhibited good solubility in organic solvents due to bulky propeller-like triphenylamine and butterfly-like conformation of phenothiazine, which were convenient for the polymers to fabricate films and devices by spin- or inject-coating. They also revealed good thermal stability with 10% weight lost at 420°C. In addition, the polymer showed a strong yellow fluorescence at 522nm in the THF solution and irregular solvatochromic characteristic in polar solvents. Furthermore, their films had well reversible redox process in the range of 0–1.2V with the color changing from colorless neutral to red in the range of 0.80–0.85V. The calculated HOMO and LUMO energy levels of polyesters demonstrated their potential application as photoelectrical materials.


      PubDate: 2016-05-10T18:54:30Z
       
  • Modification of Eucalyptus and Spruce organosolv lignins with fatty acids
           to use as filler in PLA
    • Abstract: Publication date: Available online 9 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Oihana Gordobil, Itziar Egüés, Jalel Labidi
      Spruce (softwood) and Eucalyptus (hardwood) woods were used as raw material for lignin extraction by organosolv process. Chemical, structural and thermal characterizations of the extracted lignin samples have been performed using HPLC, GPC, FT-IR, 31P NMR, 13C NMR, DSC and TGA. Both lignins showed high purity, being Spruce lignin (OS) which presented the highest Klason lignin content (93%) and lowest sugar (0.5%) and sulphur (0.04%) content. Extracted lignin samples were chemically modified with dodecanoyl chloride fatty acid, in order to modify its thermal properties as glass transition temperature (Tg). The noticeable increase in the molecular weight and sharp decrease of Tg can be appreciated. Esterified lignins were used as filler in poly(lactic acid) (PLA) films elaborated by solvent casting in different concentrations (1, 5, 10, 25 and 50%). Mechanical, thermal and water barrier properties of prepared films were investigated. The results showed that the addition of both modified lignins contributed to greater ductility and lower stiffness, providing plasticity to PLA.


      PubDate: 2016-05-10T18:54:30Z
       
  • Comparison between two different click strategies to synthesize
           fluorescent nanogels for therapeutic applications
    • Abstract: Publication date: Available online 10 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Emanuele Mauri, Irene Moroni, Luca Magagnin, Maurizio Masi, Alessandro Sacchetti, Filippo Rossi
      The development of nanogels as nanoscale multifunctional polymer-based matrices for controlled drug and gene delivery purposes has been the subject of intense research during the last decades. Their use in biomedical field is related to the effect of their size on the interactions with living cells: only within a defined range nanoparticles could be subjected to active or passive cellular uptake. In this work we propose two methods to synthetize Rhodamine modified nanogels in order to produce nanostructures that could be traced during the cellular interactions and internalization and suitable as carrier for drugs or genes. We compared the obtained sizes and charges of both nanogels, underlining which one could be more useful for biological and therapeutic applications referring to the morphological and physico-chemical properties requested in accordance with medical needs. We also tested their cytocompatibility and their characteristic behavior as drug delivery vehicles.
      Graphical abstract image

      PubDate: 2016-05-10T18:54:30Z
       
  • A new route toward imidazoline-functionalized porous polymeric materials
           from corresponding polystyrene-polylactide diblock copolymers
    • Abstract: Publication date: Available online 10 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Joaquin Arredondo, Luis Ernesto Elizalde, Benjamin Le Droumaguet, Daniel Grande
      Novel imidazoline-functionalized diblock copolymers based on polystyrene (PS) and poly(D,L-lactide) (PLA) were synthesized as precursors to corresponding functional PS-based porous materials through a three-step sequential methodology starting from an asymmetric heterobifunctional initiator. α-Hydroxyl poly(4-cyanostyrene-co-styrene) random copolymers were first obtained via an atom transfer free-radical polymerization (ATRP) procedure by varying the amount of 4-cyanostyrene in the comonomer feed. Cyano groups were then transformed into corresponding imidazoline rings. Subsequently, the microwave-assisted ring-opening polymerization (ROP) of d,l-lactide from the imidazoline-functionalized PS-based macroinitiators allowed for the generation of semi-degradable diblock copolymers with different PLA volume fractions so as to develop microphase-separated morphologies. The precursors and resulting copolymers were analyzed by 1H, 13C NMR, and FT-IR spectroscopy. Upon induced shear-flow via channel-die processing, oriented materials constituted of PLA nanodomains in a polystyrene-based continuous matrix were formed. Hydrolysis in alkaline conditions of the PLA sacrificial block yielded imidazoline-functionalized porous PS-based matrices. The resulting porous frameworks were analyzed by scanning electron microscopy (SEM) and nitrogen sorption porosimetry.


      PubDate: 2016-05-10T18:54:30Z
       
  • Tetraphenylthiophene-terminated poly(acrylic acid) as pH- and bio-sensors
           by the aggregation-induced emission property
    • Abstract: Publication date: Available online 10 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Deng-Jie Yang, Li-Yang Lin, Po-Chiao Huang, Jhen-Yan Gao, Jin-Long Hong
      Amphiphilic poly(acrylic acid) terminated with tetraphenylthiophene (TP) was prepared by atom transfer radical polymerization (ATRP) of t-butyl acrylate monomer, initiated by amino-functionalized TP, and the following by acid-catalyzed hydrolysis. With the hydrophobic TP terminal, a fluorophore with aggregation-induced emission (AIE) property, and the hydrophilic polymeric chain, the resulting polymer of TP-PAA is amphiphilic and self-assembled, through preferable hydrogen bond interactions among the carboxylic acid pedants, in water to form aggregates with strong AIE-related emission. The convenient dispersion of TP-PAA aggregates in water facilitated its applications as fluorescent sensor for pH value and for the natural protein of bovine serum albumin (BSA). Fluorescence variations in term of aggregation level of the TP terminals in different environments will be discussed in this study.


      PubDate: 2016-05-10T18:54:30Z
       
  • Fabrication of self-cross-linking fluorinated polyacrylate latex particles
           with core-shell structure and film properties
    • Abstract: Publication date: Available online 26 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Ting Lü, Dongming Qi, Dong Zhang, Qian Liu, Hongting Zhao
      A series of self-cross-linking fluorinated polyacrylate latex particles with core-shell structure were successfully prepared by one-step miniemulsion polymerization of methyl methacrylate (MMA), butyl acrylate (BA), dodecafluoroheptyl methacrylate (DFMA), and γ-methacryloxypropyl triisopropoxidesilane (MPS). The core-shell structure of the latex particles was confirmed and the latex films were characterized. Results showed that the latex films not only showed enhanced thermostability but also exhibited good hydrophobic property with the incorporation of a small amount of MPS (below 5wt% of monomers). This core-shell fluorine/silicone-containing polyacrylate latex could potentially be used for developing advanced multifunctional protective coatings such as antiwetting, anti-icing, antifogging, and anticorrosion.


      PubDate: 2016-04-29T18:48:56Z
       
  • Multifunctionality of self-assembled nanogels of curcumin-hyaluronic acid
           conjugates on inhibiting amyloid β-protein fibrillation and
           cytotoxicity
    • Abstract: Publication date: Available online 27 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Zhiqiang Jiang, Xiaoyan Dong, Hu Liu, Yongjian Wang, Lei Zhang, Yan Sun
      Aggregation of amyloid β-protein (Aβ) is a major pathological hallmark of Alzheimer's disease. Curcumin has been recognized as an inhibitor of Aβ aggregation, but its low water solubility and bioavailability limits its clinical applications. In this work, we conjugated curcumin to hyaluronic acid and drastically improved its solubility and stability. We found that the conjugates self-assembled into nanosized hydrogels that inhibited Aβ fibrillogenesis and mitigated the amyloid cytotoxicity more efficiently than free curcumin. More importantly, we found that there was an optimal curcumin substitution degree, at which the hydrogel exhibited the strongest inhibitory effect. Based on these findings, a mechanistic model was proposed. It suggested that besides the inhibitory effect of the conjugated curcumin, HA provided three synergistic functions. The first is that curcumin encapsulation into nanogels protected cells from the toxicity of free curcumin. The second was an isolation effect of the hydrogel network, which hindered the interactions between Aβ molecules. The third was the counteraction of the hydrophobic binding between Aβ and the conjugated curcumin against the electrostatic repulsion between the like-charged Aβ and HA. The two opposite forces could stretch the conformation of Aβ monomers, slowing down the aggregation and/or leading to off-pathway aggregations. This work offered new insights into the development of more potent nanoparticles for inhibiting Aβ fibrillogenesis and cytotoxicity.


      PubDate: 2016-04-29T18:48:56Z
       
  • Photoinduced detachment of cells adhered on 2-methacryloyloxyethyl
           phosphorylcholine polymer with cell binding molecule through
           photocleavable linkage
    • Abstract: Publication date: Available online 27 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Batzaya Byambaa, Tomohiro Konno, Kazuhiko Ishihara
      We prepared a novel substrate that its surface properties, e.g., cell adhesivity can be precisely and independently controlled by photoirradiation. The control of surface properties was achieved through an amphiphilic photoresponsive polymer; poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)-co-4-[4-(1-hydroxyethyl)-2-methoxy-5-nitrophenoxy]butyric acid (PL)) (PMB-PL). The PL unit can be cleaved into two parts via the external photoirradiation, which allows a successful detachment of cells adhered on the material surface. We immobilized epidermal growth factor (EGF) onto PMB-PL surface through a condensation reaction with carbonyl group on PL units to increase binding ability to specific cells. The EGF receptor overexpressed human skin epidermoid carcinoma epithelial cells (A431 cells) were used as a model cell line. The number of adhered cells was significantly increased on the EGF conjugated surface comparing to bare PMB-PL surface, although there was no cell attachment observed on poly(MPC-co-BMA) surface. The surface immobilized EGF also helped to enlarge the adherent areas of cell morphologies on surface, in contrast with an observation of round-shaped morphologies of adhered cells on bare PMB-PL surface. A simple photoirradiation procedure caused a successful detachment of adherent cells from the surface both PMB-PLs without and with immobilized EGF. The detached cells by photoirradiation were exhibited a very high cell viability and active proliferation rate as well as the non-irradiated control cells. Here, we demonstrated an easy way to immobilize biologically active molecules onto PMB-PL surfaces. We observed that immobilized bioactive molecules clearly affect the cellular morphologies and increase the efficiency of photoinduced detachment from the surface. We believe that the PMB-PL substrate can be a promising cell-collection platform for cell-based analysis through immobilized bioactive molecules, e.g., EGF that controls cellular behavior on 2D surface.


      PubDate: 2016-04-29T18:48:56Z
       
  • Comparing homogeneous and heterogeneous routes for ionic crosslinking of
           chitosan membranes
    • Abstract: Publication date: Available online 20 April 2016
      Source:Reactive and Functional Polymers
      Author(s): J.S. Marques, J.A.O.D. Chagas, J.L.C. Fonseca, M.R. Pereira
      H2SO4 — ionically crosslinked chitosan membranes were prepared via homogeneous and heterogeneous routes. The control variable in homogeneous crosslinking was the SO4 2−/NH3 + molar ratio (1:4 e 1:6) while for heterogeneous crosslinking it was the immersion time of pure chitosan membrane in H2SO4 0.5M aqueous solution (5 and 30min). FTIR-ATR suggested lower crosslinking degree for homogeneous crosslinking, corroborated by XRD analysis that indicated the maintenance of the crystalline structure for such membranes. Thermal analysis showed very similar degradation processes for homogeneous and pure chitosan but quite different for heterogeneous: not only in terms of degradation temperature but also in amount and signal of heat involved. Swelling index results were very dependent on pH of medium. Particularly in acidic medium, homogeneous crosslinked membranes, presented a higher swelling capacity than the heterogeneous ones. Mechanical properties revealed that both methodologies render membranes with lower tensile strength and elongation but with Young modulus about four times higher, due to the interactions of SO4 2− groups of H2SO4 with NH3 + of chitosan. Finally, AFM images showed dramatic changes on surface topology, with reduction of roughness for heterogeneous and an increase for the homogeneous one.


      PubDate: 2016-04-24T18:47:28Z
       
  • Ring expansion-controlled radical polymerization: Synthesis of cyclic
           polymers and ring component quantification based on SEC–MALS
           analysis
    • Abstract: Publication date: Available online 20 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Atsushi Narumi, Shuhei Hasegawa, Ryo Yanagisawa, Miho Tomiyama, Masatsugu Yamada, Wolfgang H. Binder, Moriya Kikuchi, Seigou Kawaguchi
      We report a ring expansion vinyl polymerization producing cyclic polymers using a tetra(oxyethylene) (TOE)-tethered cyclic initiator for the nitroxide-mediated controlled radical polymerization (NMP). Styrene (St) was polymerized with the cyclic NMP initiator 1 in the bulk to produce polymer 2. Structural analyses of 2 were performed by a size exclusion chromatograph equipped with a multiangle laser light scattering (SEC–MALS) detector, focusing on the relationships between the z-averaged root-mean-square radii of gyration (〈S 2〉z 1/2) versus the molecular weights. The results proved that 2 would consist of ring components as a result of the ring expansion polymerizations and radical ring crossover reactions together with ring-opened linear components, in which the amount of ring components increased with the increasing molecular weights. The data also enabled the quantification that approximately 13–40wt% of the final polymer 2 could be identified as the ring species in the M w range of 1×105–5×105 gmol−1.


      PubDate: 2016-04-24T18:47:28Z
       
  • DMAP-based flexible polymer networks formed via Heck coupling as efficient
           heterogeneous organocatalysts
    • Abstract: Publication date: Available online 22 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Wei Xu, Wu Xia, Yukun Guan, Yiming Wang, Cuifen Lu, Guichun Yang, Junqi Nie, Zuxing Chen
      Two DMAP-based flexible polymer networks TPB-DMAP and TPA-DMAP have been successfully synthesized via palladium catalyzed Heck cross-coupling. The structures of these polymers were confirmed by solid state 13C CP/MAS and Fourier transform infrared spectroscopy (FTIR). Although both polymers have negligible surface areas, they exhibit excellent catalytic efficiency for the acylation of 1-phenylethanol with acetic anhydride due to their good swelling capacities. Utilized as a typical catalyst, the polymer TPA-DMAP shows high activities for acylation of a variety of alcohols to the corresponding esters. Moreover, the catalyst can be recycled at least ten times without obvious loss of catalytic activity.


      PubDate: 2016-04-24T18:47:28Z
       
  • High performance polymer nanocomposites for additive manufacturing
           applications
    • Abstract: Publication date: Available online 19 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Al C. de Leon, Qiyi Chen, Napolabel B. Palaganas, Jerome O. Palaganas, Jill Manapat, Rigoberto C. Advincula
      Additive manufacturing (or 3D printing) involves the process of fabricating a part by layer-by-layer assembly of materials with processes such as extrusion, binding, melting, and photopolymerization. It is transforming how we assemble our prototypes and, in the future, manufacture our products. There have been a number of materials that can be utilized for this technology, however, high performance polymer nanocomposites are a very important class of material that is just recently being used in additive manufacturing. High performance polymer is a group of polymer materials that are known to retain its desirable mechanical, thermal, and chemical properties when subjected to harsh environment such as high temperature, high pressure, and corrosive chemicals. When mixed with nanofillers such as carbon nanotube, nanoclay, and graphene, these polymers can have improved mechanical properties and sometimes acquire properties that were not present initially like thermal and electrical conductivity. This review article aims to summarize available additive manufacturing techniques, high performance polymers and nanofillers available, and research efforts on its use for additive manufacturing.


      PubDate: 2016-04-19T07:53:01Z
       
  • Modification of stress-strain behaviour in aromatic polybenzoxazines using
           core shell rubbers
    • Abstract: Publication date: Available online 14 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Elliot Douse, Sotirios Kopsidas, David Jesson, Ian Hamerton
      2,2-Bis(3,4-dihydro-3-phenyl-2H-1,3-benzoxazine)propane (BA-a) is blended with a commercial core shell rubber (CSR), Genioperl P52, based on a siloxane core and an acrylic shell, at a range of loadings (1–32wt.%). Scanning electron microscopy and energy-dispersive X-ray analysis reveals an even distribution with good cohesion between the resin and CSR particles. Measurements carried out by dynamic mechanical analysis and thermogravimetric analysis show modest improvements in glass transition temperature (3%) and significant enhancement of thermal stability (20%) when CSR (32wt.%) was incorporated. Such improvements are linearly related to CSR content. Moderate reductions in modulus (30%) were observed with the highest (32wt.%) loadings of CSR and were also linearly proportional to CSR content. Thermal analysis demonstrated a small inhibitory effect, with activation energy raised by 4% with the blend containing 32wt.% CSR and 3% in the blend containing 8wt.% CSR. It was found that mechanical stirring of the CSR particles into the molten BA-a monomer was the most practical solution for dispersion and effectively broke down CSR agglomerates in the bulk and produced void free samples upon curing, although some minor defects were apparent with higher loadings of core shell rubber. Four batches of dog bone specimens (containing 0, 8, 16 and 32wt.% CSR) were manufactured and underwent tensile testing. An average increase in extension was observed from 0.82mm for the pristine poly(BA-a), to 1.14mm (32wt.% CSR) was achieved. The introduction of CSR has a deleterious impact on tensile strength (24.67MPa, pristine poly(BA-a) compared with 20.48MPa containing 32wt.% CSR; Young's modulus of 5.4GPa for pristine poly(BA-a) compared with 3.1GPa containing 32wt.% CSR). Following tensile tests, scanning electron microscopy reveals rubber cavitation as the principal toughening mechanism.
      Graphical abstract image

      PubDate: 2016-04-15T07:46:09Z
       
  • Ultra-fine silver nanoparticles dispersed in mono-dispersed amino
           functionalized poly glycidyl methacrylate based microspheres as an
           effective anti-bacterial agent
    • Abstract: Publication date: Available online 14 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Yuanming Deng, Jiefeng Li, Yitao Pu, Yuemei Chen, Jinlai Zhao, Jiaoning Tang
      In this study, amino functionalized poly glycidyl methacrylate (am-PGMA) based microspheres prepared via soap-free emulsion polymerization were served as polymeric matrices for silver nanoparticles (Ag NPs) loading and applied as anti-bacterial agent. The amino and hydroxyl enriched am-PGMA based microspheres served as both matrix for Ag+ absorbance through coordination bond and reduce agent under hydrothermal condition in a high-pressure steam sterilization. The effects of chemical structure of microspheres on the morphology of Ag NPs/polymer composites were investigated. Am-PGMA/Ag composite spheres with ultra-fine Ag NPs up to 26wt% were well characterized and their antibacterial activity were studied and discussed in detail. It was found that the Ag NPs loading in microspheres showed comparable anti-bacteria activities in terms of Ag with the minimum inhibitory concentration (MIC) low to 20 and 20mg/L (equal to 5.2, 5.2mg/L Ag) for Escherichia coli and Staphylococcus aureus respectively. The obtained composites spheres (am-PGMA/Ag) are promising alternative anti-bacterial agents in industrial and biomedical applications.


      PubDate: 2016-04-15T07:46:09Z
       
  • Negatively charged hydrophobic nanoparticles inhibit amyloid
           β-protein fibrillation: The presence of an optimal charge density
    • Abstract: Publication date: Available online 9 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Hongchen Liu, Baolong Xie, Xiaoyan Dong, Lei Zhang, Yongjian Wang, Fufeng Liu, Yan Sun
      Self-assembly of amyloid β-protein (Aβ) is closely related to the pathogenesis of Alzheimer's disease (AD). Many studies suggest that polymeric nanoparticles (NPs) can inhibit Aβ fibrillogenesis depending on their electrostatic and hydrophobic properties, but the underlying molecular mechanism remains unknown. Herein, the inhibitory effect of NPs with equivalent content of hydrophobic groups but different surface negative charge densities on Aβ fibrillogenesis is examined. Firstly, the polymeric NPs of similar sizes were synthesized by copolymerizing equal proportion of N-isopropylacrylamide and different proportion of N-t-butylacrylamide and acrylic acid. Then, the inhibitory effects of these NPs on Aβ42 fibrillization and the corresponding cytotoxicity were investigated using thioflavin T fluorescent assay, transmission electron microscopy, dynamic light scattering analysis, and cell viability assay. It was found that these NPs showed remarkable inhibitory capability against Aβ42 fibrillogenesis and alleviated its cytotoxicity. The inhibitory capability significantly depended on the capacity of the negative surface charges carried by NPs with an increase-decrease trend. The best inhibitory efficiency was obtained at an optimal surface negative charge density. Based on the findings, a mechanistic model was proposed by considering the two interactions between Aβ42 and NPs, namely, hydrophobic binding and electrostatic repulsion. The model suggested that at an appropriate negative charge capacity, the two opposite forces could be well-balanced, and thus led to the stretching of Aβ42 molecules instead of the formation of a harmful β-sheet structure. The polymeric NPs of well-designed surface of proper hydrophobicity and negative charge density could thus significantly slow down the Aβ42 fibrillation and/or result in an off-pathway aggregation with reduced cytotoxicity.


      PubDate: 2016-04-15T07:46:09Z
       
  • Melamine-based dendronized magnetic polymer in the adsorption of
           Pb(ΙΙ) and preconcentration of rhodamine B
    • Abstract: Publication date: Available online 10 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Mostafa Hossein Beyki, Farzaneh Feizi, Farzaneh Shemirani
      In this research, magnetic BaFe2O4 nanoparticles (NPs) have been synthesized via the sol-combustion process using triethanolamine as fuel. Thereinafter, the silica coated NPs have been reacted with carbon disulfide and melamine to prepare magnetic polytriazine-thiourea dendronized nanohybrid. Prepared materials have been characterized by XRD, FT–IR, VSM, EDX, TGA, BET and FE–SEM techniques. In view of potential application, the nanohybrid was employed for rhodamine B (RB) preconcentration as well as Pb(II) adsorption from aqueous solutions. Results showed that equilibrium time for both analytes obtained within 5min as RB and lead adsorption followed second order adsorption mechanism. Moreover, adsorption process followed the Freundlich isotherm model for the target analytes. Adsorbed RB and lead have been released from the sorbent surface with ethanol and HNO3 solution (0.1molL−1), respectively. Moreover, the sorbent showed good reusability after 5cycles of sorption and desorption.


      PubDate: 2016-04-15T07:46:09Z
       
  • Effect of poly(ε-caprolactone) as plasticizer on the properties of
           composites based on polylactide during hydrolytic degradation
    • Abstract: Publication date: Available online 11 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Ewa Olewnik-Kruszkowska, Patrycja Kasperska, Izabela Koter
      The aim of this work was to determine the impact the plasticizing agent has got on hydrolytic degradation of polylactide-based composites in the form of films. The research involved polylactide composites where Nanofil2 or Montmorillonite K10 were used as nanoclays and (poly(ε-caprolactone)) was introduced into the polymer matrix as plasticizer. Hydrolysis was carried out in phosphate buffer solution (pH7.40) at 37°C. Degradation process of polylactide-based composites was studied by incubating samples in 100ml solution for a maximum of 180days. In order to determine the influence of the plasticizer on hydrolysis, the materials were investigated by various analytical techniques. Thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) were used in order to investigate the thermal properties of samples during the degradation process. Gel permeation chromatography (GPC) was used to observe the decomposition of the polyesters. Morphology and structural changes during controlled hydrolysis were studied by atomic force microscopy (AFM). The results suggest that introduction of plasticizer into pure polymer as well as into PLA-montmorillonite system accelerates decompositions of investigated materials.


      PubDate: 2016-04-15T07:46:09Z
       
  • Physicochemical characterisation of hawthorn pectins and their performing
           in stabilising oil-in-water emulsions
    • Abstract: Publication date: June 2016
      Source:Reactive and Functional Polymers, Volume 103
      Author(s): J.C. Cuevas-Bernardino, C. Lobato-Calleros, A. Román-Guerrero, J. Alvarez-Ramirez, E.J. Vernon-Carter
      The physicochemical characteristics, intrinsic viscosity, adsorption dynamics and emulsifying properties of two hawthorn accessions pectins (HP50 and HP55) were evaluated and compared to those obtained for commercial citrus pectin (CP). Mark-Houwink-Kuhn-Sakurada coefficients, a MHKS =0.71±0.02 and k MHKS =5.08×10−3 ±2×10−4 gdL−1 were obtained from intrinsic viscosity data. The diffusion (K diff ), penetration (K 1) and the rearrangement (K 2) constants were determined from adsorption dynamics data of the pectins at the canola oil-water interface. K diff was higher and K 1 was lower for HP50 than for HP55 and for CP. These results had bearing on the stability of oil-in-water emulsions. Higher K diff produced smaller initial droplet sizes, due to the faster diffusion of molecules to the interface, while lower K 1 produced longer-term stability, as a more consolidated and stronger interfacial film was formed faster, making arduous the penetration of newly arriving molecules through the monolayer. The rate of creaming was lower the smaller was the initial droplet size and the higher the apparent viscosity of the emulsions.


      PubDate: 2016-04-15T07:46:09Z
       
  • Preparation and characterization of porous scaffolds from
           chitosan-collagen-gelatin composite
    • Abstract: Publication date: Available online 14 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Robert Tylingo, Grzegorz Gorczyca, Szymon Mania, Piotr Szweda, Sławomir Milewski
      Novel porous scaffolds composed of chitosan, collagen and gelatin were prepared and characterized. For preparing scaffolds gelatin and collagen isolated from fish skins with various physicochemical properties were used. In order to reduce preparation solubility glutaraldehyde in the amount of 1%, w/w relative to the total biopolymers weight in solution was used. All obtained biomaterials showed a homogeneous porosity. Protein polymer type determined the rheology and mechanical properties of obtaining preparations. The use of protein polymers decreased swelling capacity of materials approximately 30% compared to the materials obtained from chitosan. Materials containing gelatin showed the highest solubility (approx. 30%). Scaffolds obtained in 100% of chitosan proved to be harder than collagen materials an average of 30% and less flexible more than twice. In relation to the gelatin materials were characterized by smaller values of both measured parameters on average 40% and 30% respectively. Materials containing protein polymers showed good antioxidant properties.


      PubDate: 2016-04-15T07:46:09Z
       
  • Porous polyimide framework: A novel versatile adsorbent for highly
           efficient removals of azo dye and antibiotic
    • Abstract: Publication date: Available online 6 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Yan Wang, Qiang Gao, Qingliang You, Guiying Liao, Hua Xia, Dongsheng Wang
      Porous organic frameworks (POFs) have aroused considerable interest owe to its high surface areas, superior chemical and thermal stabilities, good mechanical and abundant porosity. In this study, a porous polyimide (PI) with abundant amine groups was synthesized by the reaction of melamine and pyromellitic dianhydride. And its versatile adsorption performance towards organic pollutants, including azo dye (methyl orange (MO)) and antibiotic (tetracycline (TC)) was investigated. The PI was characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FE-SEM), thermogravimetric analysis (TGA), and N2 adsorption-desorption techniques. The obtained product possessed high thermal stability and exhibited a high surface area (635.5m2·g−1) and a large pore volume (0.98cm3·g−1). The pH effect study showed that MO adsorption was highly pH-dependent with an optimal pH3, while the TC adsorption was effective in the pH range of 6–8. Batch adsorption experiments were carried out to study adsorption kinetics and adsorption thermodynamics. The result showed that the kinetics experimental data were fitted to pseudo-second-order kinetics model better, and adsorption isotherm could be described by the Langmuir isotherm model perfectly. The maximum adsorption capacities calculated from the Langmuir isotherm model are 609.8 and 155.8mg/g at 318K for MO and TC, respectively. The thermodynamic study showed that the adsorptions of TC and MO on PI were spontaneous (ΔG <0) and endothermic (ΔH >0). Findings in this study demonstrated that the porous PI should be a powerful adsorbent in organic pollutants removal.


      PubDate: 2016-04-09T06:00:15Z
       
  • Quantitative determination of acidic groups in functionalized graphene by
           direct titration
    • Abstract: Publication date: Available online 6 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Jakub Ederer, Pavel Janoš, Petra Ecorchard, Václav Štengl, Zuzana Bělčická, Martin Šťastný, Ognen Pop-Georgievski, Vlastimil Dohnal
      Direct titration with NaOH was used to quantify the acidic functional group content in graphene oxide (GO). Three different methods were used to evaluate the experimental data: the first derivation of the titration curve, Gran linearization and an empirical approach suggested by Ritchie and Perdue for the evaluation of the titration data for humic substances. Two types of acidic functional groups were identified and classified, more or less arbitrarily, as being either carboxylic or phenolic. Typically, the carboxylic acid group contents ranged from ca. 0.80 to 1.70mmol/g, except for the carboxylated GO prepared by the reaction with chloroacetic acid, which contained significantly more carboxylic acid groups. The titration results are consistent with those obtained by instrumental methods such as X-ray diffraction (XRD), infrared spectroscopy (IR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). For modelling purposes (proton binding and metal binding), a bimodal continuous distribution model was proposed, and its parameters were estimated from the titration data.


      PubDate: 2016-04-09T06:00:15Z
       
  • Facile synthesis of amphiphilic poly(ethylene glycol) conjugate and its
           micellization as injectable targeted vehicle for DOX
    • Abstract: Publication date: Available online 7 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Jin Zeng, Peng Liu
      Amphiphilic FA-PEG2000-OA conjugate was designed, comprising hydrophilic poly(ethylene glycol) (PEG), with a folate targeting moiety and a biodegradable hydrophobic oleic acid (OA) segment at each chain ends. The near-monodisperse flower-shaped folate-functionalized micelles were self-assembled in aqueous solution for the folate receptor (FR)-mediated targeted delivery of the anticancer drug (doxorubicin (DOX)) to cancer cells. The drug loading and in vitro pH responsive controlled release performance revealed that the FA-PEG2000-OA micelles had potential application as drug delivery systems (DDS) for hydrophobic anthracycline anti-cancer drugs such as DOX. With the aid of FA-PEG2000-OA micelles as DDS, which was non-cytotoxic in low concentrations, the cancer cell-killing ability of DOX has been obviously enhanced, demonstrating their promising applications to overcome multi-drug resistance (MDR) in tumor treatments.


      PubDate: 2016-04-09T06:00:15Z
       
  • Preparation of a thermosensitive fiber and its carbon dioxide
           adsorption/desorption properties
    • Abstract: Publication date: Available online 9 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Yu Wang, Fengqin Yin, Shuixia Chen, Xiaotong Peng
      A thermosensitive fiber (VF-NIPAAM-co-AM) was developed by grafting N-isopropylacrylamide (NIPAAM) and acrylamide (AM) onto the surface of viscose fiber (VF) through the simultaneous grafting copolymerization approach. The grafted fiber was subsequently aminated with triethylenetetramine (TETA) to prepare a solid amine adsorbent for CO2 capture. The effect of NIPAAM/AM molar ratio on the thermosensitive properties of the grafted fiber was investigated. It was found that the contact angle of VF-NIPAAM-co-AM increased with the increasing of NIPAAM/AM molar ratio. For all the prepared fibers, the contact angle of VF-NIPAAM-co-AM at 343K was higher than that at 293K, indicating the thermosensitive property of the grafted copolymer fibers. After amination, the contact angle of VF-NIPAAM-co-AM-TETA at 293K and 343K were 79.86°and 84.14°, respectively. Even though the contact angles of aminated fibers decreased, the fiber still retained a certain thermosensitive property. Studies on the adsorption and desorption behaviors of VF-NIPAAM-co-AM-TETA and VF-AM-TETA indicated that CO2 could be more efficiently and completely desorbed from VF-NIPAAM-co-AM-TETA at 80°C than from VF-AM-TETA, a structurally similar fiber but without NIPAAM.


      PubDate: 2016-04-09T06:00:15Z
       
  • Synthesis and photophysical study of some new highly thermostable blue
           
    • Abstract: Publication date: Available online 2 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Corneliu Hamciuc, Mihaela Homocianu, Elena Hamciuc, Ionela-Daniela Carja
      New poly(1,3,4-oxadiazole-imide)s were synthesized from a diamine containing 1,3,4-oxadiazole ring, 4.4′-diamino-4″-[(2-(4-phenoxy)-5-(4-dimethylaminophenyl)-1,3,4-oxadiazole]triphenylmethane, and different aromatic dianhydrides: 4.4′-(hexafluoroisopropylidene)diphthalic anhydride, 9.9-bis[(3.4-dicarboxyphenoxy)phenyl]fluorene dianhydride, 4.4′-(4.4′-isopropylidenediphenoxy)bis(phthalic anhydride) and perylene-3,4,9,10-tetracarboxylic dianhydride. The polymers were easily soluble in polar organic solvents and exhibited high thermal stability, having 5% weight loss in the range of 445–470°C and glass transition temperature in the domain of 201–244°C. The optical properties were investigated in different media. The absorption characteristics (intensity, absorption maximum and shape) of investigated compounds depended on their chemical structures and the nature of environment. The emission of these samples was represented by one broadened and blue emission band. The largest and solvent dependent Stokes shifts values were obtained. The fluorescence quantum yield (QY) values of polymer with hexafluoroisopropylidene groups, in tetrahydrofuran solution, depended on the wavelength used for excitation. This is an exception from Kasha's rule and Vavilov's law, which was attributed either to photodecomposition or to the enhancement of intramolecular energy transfer process competing with internal conversion between singlet states. High QY values were obtained for polymers with isopropylidene or fluorene units in dimethyl sulfoxide (polar solvent), which may be due to the strong overlap of electronic transitions of species from system.


      PubDate: 2016-04-06T02:28:04Z
       
  • Experimental and theoretical study of molecular interactions between
           2-vinyl pyridine and acidic pharmaceuticals used as multi-template
           molecules in molecularly imprinted polymer
    • Abstract: Publication date: Available online 2 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Lawrence Mzukisi Madikizela, Phumlani Selby Mdluli, Luke Chimuka
      Molecular interactions between functional monomer and template molecules are regarded as the driving force for the success of a molecularly imprinted polymer. In this study, a multi-template molecularly imprinted polymer (MIP) for ibuprofen, naproxen and diclofenac was synthesized in an oil bath set at 70 °C for 24 hours. 2-vinyl pyridine, ethylene glycol dimethacrylate, toluene and 1,1’-azobis-(cyclohexanecarbonitrile) were used as functional monomer, cross-linker, porogen and radical initiator, respectively. A non-imprinted polymer (NIP) was synthesized using a similar approach with the omission of templates. Monomer-template interactions were examined using Molecular Dynamics and Fourier Transform Infrared Spectroscopy (FTIR). Both molecular dynamics and FT-IR results indicated the formation of the hydrogen bond between the templates and 2-vinyl pyridine. Molecular dynamics further revealed the identity of the hydrogen atoms in the templates involved in interactions with nitrogen atom on the functional monomer in the presence of toluene molecules. Surface area obtained for the MIP using Brunauer, Emmett and Teller method was 282 m2/g, whereas 232 m2/g was obtained for the NIP. This indicated that MIP has more binding sites compared to the NIP. Furthermore, batch adsorption and selectivity experiments were carried out in the presence of gemfibrozil as the competitor. When such experiments were carried out in toluene, the adsorption capacities (mg/g) obtained for naproxen, ibuprofen, diclofenac and gemfibrozil were 14.4, 11.0, 14.0 and 7.5, respectively. These results show that the MIP was more selective to the compounds that were used as template molecules.
      Graphical abstract image

      PubDate: 2016-04-06T02:28:04Z
       
  • Bioinspired double-positively charged phosphodicholine-chitosan and
           zwitterionic phosphorylcholine-chitosan conjugates: The associated water
           structure, biocompatibility and antibacterial action
    • Abstract: Publication date: Available online 24 March 2016
      Source:Reactive and Functional Polymers
      Author(s): Zhaoyu Cao, Minming Wu, Yunfei Zhao, Lisha Dai, Rong Zeng, Mei Tu, Jianhao Zhao
      Bioinspired double-positively charged phosphodicholine (PdC)-chitosan conjugate was synthesized via Atherton-Todd reaction, which can hydrolyze to zwitterionic phosphorylcholine (PC)-chitosan in basic solutions, confirmed by 1H and 31P NMR spectra. Thermal analysis revealed that there existed the freezing bound water due to the introduction of PdC and PC groups for both PdC-chitosan and PC-chitosan, implying that double-positively charged PdC-chitosan may exhibit excellent biocompatibility as zwitterionic PC-chitosan. Cytotoxicity, hemolysis and antibacterial activity evidenced that PdC-chitosan displayed high antibacterial activity against Escherichia coli and Staphylococcus aureus under physiological conditions, and very low cytotoxicity and hemolytic activity, owing to its highly selective lysis of bacterial membranes over mammalian cell membranes mainly resulting from the competition of electrostatic interactions and shielding effect of the restrained water of PdC, while biocompatible PC-chitosan showed no antibacterial activity due to its non-fouling property. The results indicated that biocompatible double-positively charged PdC-containing bioinspired polymers may provide a promising approach for developing safe and effective antibacterial agents.


      PubDate: 2016-03-27T14:36:47Z
       
  • Biocatalytic protein membranes fabricated by electrospinning
    • Abstract: Publication date: Available online 25 March 2016
      Source:Reactive and Functional Polymers
      Author(s): Gözde Kabay, Gizem Kaleli, Zahida Sultanova, Tolga Tarkan Ölmez, Urartu Özgür Şafak Şeker, Mehmet Mutlu
      In this study, a protein-based catalytic membrane was produced by electrospinning. Membrane activity was characterised in terms of response current for various glucose concentrations. We focused on the preparation of a scaffold by converting a globular protein to other structural forms using catastrophic solvents. A scaffolding protein, bovine serum albumin, and an enzyme, glucose oxidase (GOD), were selected as a model natural carrier matrix and a biologically active agent, respectively. Beta-mercaptoethanol (β-ME) was used to convert the globular protein to an amyloid-like form. A structural stabilising agent, 2,2,2-triflouroethanol (TFE), was used to maintain the final α-helical structure of the amyloid-like protein. The TFE:PBS (phosphate-buffered saline) ratio and various electrospinning parameters were analysed to minimise activity loss. Using this approach, we applied electrospinning to an active enzyme to obtain biocatalytic nanofibrous membranes. After optimising the protein electrospinning process, the activities of the protein nanofibrous membranes were monitored. GOD remained active in the new membrane structure. The highest enzyme activity was observed for the membranes prepared with a 1.5:1 (v:v) TFE:PBS solvent ratio. In that particular case, the immobilized enzyme created a current of 0.7μA and the apparent activity was 2547±132U/m2.


      PubDate: 2016-03-27T14:36:47Z
       
 
 
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